Color small amounts of gum paste in orange, green, and purple to cut keys. Using white gum paste and large hole, extrude a rope to be used to put the keys on. Roll and cut keys; allow to dry. Cut baby bootie, assemble, and allow to dry. Extrude two small ropes for laces of booties and lace booties. Using a small round tip and royal icing, outline booties Cover 9" x 13" cake with pastel blue fondant then cover 6" cake with pastel yellow fondant. Place 6" cake on larger cake; attaching with a small amount of buttercream. Place a dowel rod down the center of the 6" to secure. Attach booties to top of 6" cake with piping gel. Attach cut-out letters to side of large cake. Using a round tip, pipe a bead border around both cakes. Attach baby blocks with piping gel and lay keys on top of cake.